The present invention relates generally to plier tools such as retaining or snap ring pliers. More particularly, the present invention relates to pliers of a type which are convertible between a first position which allows the jaws to move inwardly as the handles are moved inwardly and a second position which allows the jaws to move outwardly as the handles are moved inwardly.
Retaining rings are utilized in annular grooves on shafts and ends of shafts to retain bearings, collars, and the like on the shaft. A retaining ring extends circumferentially between a pair of ends which are formed to have hubs. The hubs have apertures in which are inserted tips of a plier tool and force applied to either spread the hubs to expand the ring or squeeze the hubs to contract the ring, as necessary for installing the ring in and removing the ring from either external or internal grooves.
It is thus sometimes considered desirable to squeeze (move inwardly) the handles to effect movement of the jaws outwardly to expand the ring. It is at other times considered desirable to squeeze the handles to effect movement of the jaws inwardly to contract the ring. Thus, it is desirable to provide a plier which is convertible between an external and an internal tool. U.S. Pat. Nos. 4,280,265 and 4,476,750 disclose a pair of retaining ring pliers which utilize a pair of separate coplanar jaws and a pair of separate handles arranged about a common fixed pivot point having a pair of fulcrum points adapted to alternately engage one handle then another to change the fulcrum point to permit the changing of the tool from an external to an internal tool. Two fulcrum pins are disposed in the jaws and adapted to alternately engage each set of handles to shift the fulcrum point from a position adapted to move the jaws inwardly as the handles are moved inwardly to a position where the jaws are moved outwardly as the handles are moved inwardly. It may be difficult for the user of the pliers of the above patents to slide the pins into position.
What is needed is a convertible plier tool that is easier to manipulate between the internal and external configuration.
The present invention meets the above-described need by providing first and second jaws independently and rotatably disposed about a pivot. A separate pair of handles are rotatably disposed about the same pivot. The handles attach on opposite sides of the jaws by a bolt that passes through openings in the handles and through the center of the jaws. The jaws have a recessed portion with a bearing surface that abuts with the tops of the handles. The handles are capable of being alternately engaged with the jaws such that the tool is changeable between a first position where the first jaw in engaged with the first handle and the second jaw is engaged with the second handle and a second position where the first jaw is engaged with the second handle and the second jaw is engaged with the first handle. In this manner, the tool can be switched from an internal retaining ring plier to an external retaining ring plier. When the tool is set for external rings, the jaws move outwardly when the handle moves inwardly. When the tool is set for internal rings the jaws move inwardly when the handles are moved inwardly. The jaws have openings at the back ends for engaging with pivoting members attached to the handles.
In a disclosed embodiment, a first pivoting member is attached to the first handle and has a pair of key elements that are sized to fit into the openings in the first jaw or the second jaw. The first pivoting member pivots about a centrally located pivot such that when it is rotated in one direction one of its key elements enters the first jaw. When the pivoting member is rotated in the opposite direction, the key element on the opposite side of the pivot enters the second jaw. Accordingly, the key members on the first pivoting member enable the member to alternately engage with either jaw pending on which way the pivoting member is rotated.
A second pivoting member is attached to the second handle and pivots about a pivot that aligns with the pivot for the first pivoting member. The second pivoting member also has a pair of key elements that operate in the same manner as described above such that the second pivoting member is capable of engaging the second handle to either the first jaw or the second jaw depending on which way the second pivoting member is rotated.
Each pivoting member has a lever arm attached to one end such that the members can be manually rotated from first positions where the first handle is engaged with the second jaw and the second handle is engaged with the first jaw to second positions where jaw to handle engagements are reversed.